Watching a bird incubate is not very exciting.
Lady Baltimore spends most of her time in the nest. So, I spend most of mine watching her sit. Or rather, watching her tail, which is mostly all that I see. By my calculations, it’s about time for her babies to start hatching, one per day for four or five days. And a cowbird, too, if the interloper I caught scoping out the nest managed to lay an egg inside.
So, I’m watching that unexciting nest closely, looking for any movement that might suggest hatchlings within.
For the initial days after Baltimore Oriole hatchlings bust out of their eggs, their parents feed them by regurgitation. I’ve seen plenty of regurgitation feedings by Pileated Woodpeckers. With those birds, the feeding movement is easy to spot, even when all you can see is a parent’s tail feathers sticking out of the nest cavity.
Here’s what I mean, taken five years ago when a pair of Pileated Woodpeckers nested in one of our trees. The video looks a little wonky, and I didn’t get any usable audio. I was holding an iPhone to the lens of our spotting scope, hence you see a vignette—the dark area surrounding what the phone’s camera could see through the lens. Watch the mom’s tail after she enters the cavity.
Pileated Woodpeckers feed by regurgitation until the kids fledge (unlike orioles, who will bring morsels to the nest after a few days). Here’s dad feeding a nestling a week later. You’ll see why mom’s tail was shaking in the first video.
And later yet, just a day or so before this juvenile fledged (and I had figured out some better video technique). This video has audio, too. If you’ve never heard a Pileated Woodpecker feeding, you might find the sound interesting.
My reason for sharing these woodpecker feedings is so you’ll understand what I’ve been looking for in the oriole nest. I suspect the orioles’ regurgitation feedings are less animated than the woodpecker version, although I haven’t found any video or articles describing the meals.
Yesterday, I thought Lady Baltimore had something in her mouth when she returned to the nest after a foraging trip. Then, when she hopped in, her shaking tail evoked my memory of that early Pileated Woodpecker feeding, when all I could see was the parent’s tail. Was Lady B feeding a hatchling in her nest?
Here’s what I saw—see if you agree she’s got something in her mouth and that her tail wiggles once she’s inside.
And then, there’s the other possible explanation—stitching. Lady B continues to poke and pull on the nest, sometimes reaching outside to tighten where she lashed it to a branch. Watch her take a few stitches yesterday. I like this video because the bright sunshine lets us see through the nest. You’ll see Lady B inside, lifting her head and poking at her weaving. And… her tail quivers, just like in the prior video.
So, in that earlier video, was Lady B feeding a hatchling? Or was she just settling in after swallowing the last of her lunch? I think it was the latter. When the eggs do hatch, I should be seeing lots of parental comings and goings, including Lord Baltimore, who will supposedly help with the feedings. But for now, Lord B is mostly out of sight as Lady B sits tight.
And so, my watch-and-wonder vigil continues.